AW: [PATCH 3/4] mci: imx-esdhc: add DSR support

[Markus Niebel]

Hello,

> Von: Alexander Aring [mailto:alex.aring at gmail.com]
> Gesendet: Dienstag, 14. Januar 2014 09:49
> An: Markus Niebel
> Cc: barebox at lists.infradead.org; Markus Niebel
> Betreff: Re: [PATCH 3/4] mci: imx-esdhc: add DSR support
> 
> Hi,
> 
> On Tue, Jan 14, 2014 at 09:23:36AM +0100, Markus Niebel wrote:
> > From: Markus Niebel <Markus.Niebel at tqs.de>
> >
> > having DSR support in mci-core we need a way to
> > forward the DSR value to the driver. Add it to
> > platform data for imx-esdhc
> >
> > TODO: implement the same for other host controller
> > drivers
> >
> > Signed-off-by: Markus Niebel <Markus.Niebel at tqs.de>
> > ---
> >  arch/arm/mach-imx/include/mach/esdhc.h |    2 ++
> >  drivers/mci/imx-esdhc.c                |    4 ++++
> >  2 files changed, 6 insertions(+)
> >
> > diff --git a/arch/arm/mach-imx/include/mach/esdhc.h b/arch/arm/mach-
> imx/include/mach/esdhc.h
> > index add1691..fb7380a 100644
> > --- a/arch/arm/mach-imx/include/mach/esdhc.h
> > +++ b/arch/arm/mach-imx/include/mach/esdhc.h
> > @@ -42,5 +42,7 @@ struct esdhc_platform_data {
> >  	enum cd_types cd_type;
> >  	unsigned caps;
> >  	char *devname;
> > +	unsigned dsr_val;
> > +	int use_dsr;
> >  };
> >  #endif /* __ASM_ARCH_IMX_ESDHC_H */
> > diff --git a/drivers/mci/imx-esdhc.c b/drivers/mci/imx-esdhc.c
> > index 7664e7b..4c7a45e 100644
> > --- a/drivers/mci/imx-esdhc.c
> > +++ b/drivers/mci/imx-esdhc.c
> > @@ -582,6 +582,10 @@ static int fsl_esdhc_probe(struct device_d *dev)
> >  	if (host->mci.f_min < 200000)
> >  		host->mci.f_min = 200000;
> >  	host->mci.f_max = rate;
> > +	if (pdata) {
> > +		host->mci.use_dsr = pdata->use_dsr;
> > +		host->mci.dsr_val = pdata->dsr_val;
> > +	}
> >
> I don't know what other barebox devs thinking about this. But I would
> remove use_dsr attribute, because a dsr_val != 0 indicates that you want
> to use dsr. You don't need a extra switch, in my opinion.

As far as I understand the documentation the assignment between DSR / CMD4 value 
and driver strength is left to the card (firmware) implementor - so far a dsr_val = 0
could be a valid setting.

> 
> - Alex

Markus